Random detuning type track vibration reduction system and design method thereof

Abstract

The invention discloses a random detuning type track vibration reduction system and a design method thereof.The structure comprises track pieces and vibration reduction units, the track pieces are arranged on a track plate in groups at intervals, the multiple vibration reduction units are arranged on the inner sides and the outer sides of the track pieces or on the track plate, and the multiple vibration reduction units on the same side of the track pieces are distributed corresponding to the longitudinal periodicity of the track pieces; the vibration reduction units on the two sides of the rail piece are symmetrically arranged or arranged in a staggered mode. The main frequency of the vibration reduction unit is close to the band gap frequency of the track structure, the vibration mode of the vibration reduction unit and the vibration mode of the track structure are mutually coupled, so that the resonance structure of the vibration reduction unit and the ballastless track structure generate a coupling effect, the band gap range is enlarged, and the mass, rigidity and installation position parameters of the vibration reduction unit are designed to be randomly distributed. According to the random detuning type design method, the vibration reduction range can be further widened, vibration of the track structure cannot be increased, the vibration reduction unit does not need to be replaced along with service time prolonging or environment changing, and the vibration reduction capacity is effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of rail transit vibration reduction and noise reduction, and in particular relates to a random detuning type rail vibration reduction system and a design method thereof. Background Art

[0002] With the rapid development of urban rail transit, the speed of trains has increased, and the impact on environmental vibration and noise has become more and more significant. The demand for vibration and noise reduction of urban rail transit tracks is prominent. The current track vibration reduction measures are mainly vibration isolation and dynamic vibration absorption. Vibration isolation measures such as vibration reduction fasteners and floating plate roadbeds insert elastic layers between track structure layers to reduce the transmission of vibration to the outside world, but at the same time they will increase the vibration of the track structure, such as vibration reduction fasteners amplifying rail vibration, and floating plate roadbeds amplifying roadbed structure vibration. Dynamic vibration absorption measures such as rail dynamic vibration absorbers and track plate dynamic vibration absorbers can transfer the vibration energy of the track structure to additional devices, but the vibration absorbers usually have a single operating frequency and a narrow vibration reduction frequency band. As the service time increases, the performance of the elastic layer deteriorates and the vibration reduction effect decreases. Therefore, it is necessary to propose a measure that can achieve broadband vibration reduction of the track structure, achieve environmental vibration control and reduce track structure vibration at the same time.

[0003] In order to increase the vibration reduction effect of vibration reduction measures, relevant researchers and technicians have carried out extensive optimization design based on the existing vibration reduction fasteners, steel spring / vibration reduction pad floating plates, rail vibration absorbers and floating plate vibration absorbers. It is mainly reflected in the following aspects:

[0004] Frequency-adjustable rail dynamic vibration absorber: In the prior art, the mass or stiffness of the vibration absorber is pre-designed to generate a resonant frequency that is compatible with the vibration frequency of the rail, so that the vibration energy of the wheel-rail main vibration system is transferred and dissipated. However, during the operation of the train, the excitation of the rail by the wheel is a constantly changing broadband excitation. For example, rail grinding or track reconstruction will cause changes in the wheel-rail excitation frequency. The existing rail tuning vibration absorbers often cannot achieve secondary frequency modulation after installation, and there are problems such as cumbersome and complicated on-site replacement operations and limited rail noise reduction effects.

[0005] Chinese patent CN114411456A discloses a mass-adjustable rail vibration absorber, which changes the working frequency of the rail vibration absorber by replacing an adjusting member of a specific mass, thereby improving the working efficiency of secondary frequency modulation.

[0006] Chinese patent CN211009410U discloses a clamp for installing a frequency modulation type rail vibration absorber, which facilitates the disassembly and assembly of the dynamic vibration absorber.

[0007] Chinese patent CN117847130A discloses a dynamic vibration absorber with adjustable frequency and mass, in which the stiffness is adjusted by compressing a rubber layer in the vibration absorber, and different vibration absorption frequencies are obtained by installing mass blocks of different masses.

[0008] Chinese patent CN116516736A discloses an adjustable rail vibration absorber, which can change the operating frequency of the vibration absorber by adjusting the number of counterweights.

[0009] Multi-frequency vibration absorber structure: In order to achieve vibration control in a wider frequency range, the existing vibration absorber structure has a single operating frequency. Chinese patent CN111778781A discloses a rigidly connected wide-band rail dynamic vibration absorption device, in which vibration absorbers are arranged on the left and right sides of the rail, and at least two or more vibration frequencies can be controlled. Chinese patent CN213328472U discloses a multi-stage rail vibration absorber, which adjusts the operating frequency by combining the mass block with the horizontal beam and adjusting the position of the mass block. Chinese patent CN201020257075.5 discloses a rail waist vibration absorber, in which three metal mass blocks are embedded in the rail waist rubber part, and the three metal blocks have different masses to improve the vibration reduction effect.

[0010] Bandgap vibration-damping structure based on phononic crystal theory: The phononic crystal structure is a structure with periodic characteristics. Due to its periodic characteristics, the vibration propagation in the phononic crystal has a bandgap effect, that is, the vibration within a specific frequency range cannot be transmitted in the phononic crystal.

[0011] Chinese patent CN110528340A discloses a phononic crystal floating plate isolator, which suppresses the transmission of floating plate vibration to the substrate by designing the steel spring into a phononic crystal structure with periodic characteristics, thereby achieving vibration reduction.

[0012] Chinese patent CN218294321U discloses a phononic crystal rail dynamic vibration absorber, the principle of which is similar to that of a dynamic vibration absorber, and vibration reduction is achieved by the combination of a mass block and an elastic layer, and the vibration reduction frequency band is increased by setting hollow steel columns of different heights.

[0013] Chinese patent CN111778783A proposes a dynamic vibration absorber with an embedded phononic crystal structure, which forms a vibration reduction structure by setting a periodically distributed multilayer structure on one side of the rail waist and then installing a mass body on the outside. However, this structure still belongs to the design of a vibration absorber.

[0014] Existing vibration reduction methods for ballastless track structures are designed based on dynamic vibration absorption, elastic vibration isolation, and phononic crystal band gaps. However, the frequency band of dynamic vibration absorbers is relatively narrow, and the frequency is mainly changed by adjusting the mass block. The vibration isolation method under the rail or floating plate will lead to increased vibration of the rail or ballast bed structure. The vibration reduction design based on phononic crystal band gaps requires that the vibration transmission path coincides with the direction of the periodic arrangement of the structure, and the band gap width is generally narrow. In order to achieve a vibration reduction effect in a wider frequency range and avoid increasing the vibration of the ballastless track structure itself due to the setting of vibration reduction measures, new vibration reduction design methods need to be studied.

[0015] Therefore, how to provide a track vibration reduction system with a wide-band vibration reduction effect and a design method thereof is a problem that those skilled in the art urgently need to solve. Summary of the invention

[0016] In view of this, the present invention provides a random detuning track vibration reduction system and a design method thereof. The existing ballastless track structure vibration reduction design adopts dynamic vibration absorbers and other technical methods, which have the disadvantages of single control frequency and reduced vibration reduction effect with installation conditions, environmental conditions or service time. By introducing a random detuning system into the ballastless track structure and coupling it with the periodic characteristics of the ballastless track structure itself, a wide-band vibration reduction band gap is generated, and the vibration noise of the ballastless track in a wide frequency range is achieved.

[0017] In order to achieve the above object, the present invention adopts the following technical solution: a random detuning track vibration reduction system, comprising:

[0018] Rail members, the rail members are arranged in groups and at intervals on the track plate, and a fastener system is arranged between the rail members and the track plate;

[0019] A vibration damping unit, wherein there are multiple groups of the vibration damping units, and the multiple groups of the vibration damping units are arranged on the inner and outer sides of the rail member or on the track plate. The multiple groups of vibration damping units on the same side of the rail member are distributed quasi-periodically in the longitudinal direction of the rail member. The vibration damping units on both sides of the rail member are arranged symmetrically or staggered. The main frequency of the vibration damping unit is close to the band gap frequency of the track structure, and the vibration mode of the vibration damping unit is coupled with the vibration mode of the track structure, so that the resonance structure of the vibration damping unit and the ballastless track structure produce a coupling effect, thereby enlarging the band gap range.

[0020] The beneficial effects of the present invention are as follows: the present invention will not weaken the integrity and strength of the track structure, the present invention is easy to install, and the vibration energy consumption of the track structure is realized by using the vibration reduction unit. At the same time, the longitudinal direction of the vibration reduction unit corresponding to the rail member presents an approximately periodic distribution characteristic, which avoids the generation of new resonance frequencies after the introduction of vibration reduction measures, and at the same time broadens the vibration control frequency range of the vibration reduction measures. The present invention is based on the concept of random detuning design and combines the band gap theory of phononic crystals to couple the elastic wave band gap of the phononic crystal with the band gap of the ballastless track structure itself to realize the vibration control of the track structure, and further designs the random detuning parameters of the vibration reduction structure, so that the resonance structure of the vibration reduction unit and the ballastless track structure produce a coupling effect, suppress the resonance peak and broaden the vibration reduction frequency band range, and maximize the vibration effect. The present invention breaks the idea of ​​periodic arrangement in the existing track structure vibration reduction design, and proposes a random detuned vibration reduction system design method suitable for ballastless track structure. Combined with the periodic characteristics of the track structure itself, approximately periodic detuned vibration reduction units are arranged in the track structure to broaden the vibration reduction frequency band, reduce the vibration of the track structure itself, reduce problems such as rail corrugation and resonance fracture of fastener spring bars caused by vibration, and at the same time reduce the transmission of track structure vibration to the outside world.

[0021] Preferably, the vibration damping unit comprises a first type of vibration damping unit and a second type of vibration damping unit, the first type of vibration damping unit is arranged on the rail member, and the second type of vibration damping unit is arranged on the track plate.

[0022] The resulting technical effect is that the vibration reduction unit of the present invention actually has two structural forms. The first structural form is suitable for installation on the rail member, and the second structural form is suitable for installation on the track plate. Regardless of the structural form, the vibration control of the track structure can be achieved, the resonance peak can be suppressed, and the vibration reduction frequency band range can be widened.

[0023] Preferably, the first type of vibration reduction unit includes a viscoelastic body, a constraint layer and a scatterer, the viscoelastic body is fixed to the side of the rail, the constraint layer is fixed to the outer side of the viscoelastic body away from the rail, the viscoelastic body is provided with a plurality of groove cavities inside, the plurality of groove cavities all pass through both ends of the viscoelastic body, and the scatterers are provided in multiple groups and are respectively installed in the groove cavities.

[0024] The resulting technical effect is that the viscoelastic body, the constraining layer and the scatterer are attached to the rail member, thereby generating a resonance effect to absorb and dissipate the vibration energy of the rail member, thereby reducing the outward transmission of the vibration energy of the track structure.

[0025] Preferably, the viscoelastic body is rubber, polyurethane or a viscoelastic damping material, the scatterer is a metal structure, and the constraining layer is a hard material plate.

[0026] Preferably, the viscoelastic body is divided into a plurality of substructures in the axial direction, and the cross section of the viscoelastic body is divided into a first half zone and a second half zone, the first half zone is close to the side of the rail member, and the second half zone is close to the side of the constraint layer, the first half zone is provided with at least a first slot cavity, a second slot cavity and a third slot cavity in sequence from top to bottom, and the second half zone is provided with at least a fourth slot cavity, a fifth slot cavity and a sixth slot cavity in sequence from top to bottom, the scatterer includes at least a first scatterer, a second scatterer, a third scatterer, a fourth scatterer, a fifth scatterer and a sixth scatterer, and they are respectively installed in the first slot cavity, the second slot cavity, the third slot cavity, the fourth slot cavity, the fifth slot cavity and the sixth slot cavity in a one-to-one correspondence, a plurality of the second scatterers and a plurality of the sixth scatterers connect a plurality of substructures in series, the first scatterer, the third scatterer, the fourth scatterer and the fifth scatterer correspond in the substructures, and the first scatterer, the third scatterer, the fourth scatterer and the fifth scatterer in adjacent substructures are periodically spaced in the axial direction.

[0027] The resulting technical effect is that the second scatterer and the sixth scatterer are actually continuous structures, the purpose of which is to connect multiple sub-structures in series, and the continuous structure is used to guide the action of elastic waves, effectively transferring the vibration of the rail to the additional vibration damping unit, and then the scatterers and viscoelastic bodies on the vibration damping unit vibrate to dissipate energy.

[0028] Preferably, at least two groups of vibration-damping units on the same side of the rail member constitute an installation group, and the vibration-damping units in the same installation group are connected in series through the second scatterer or the sixth scatterer. One side of the rail member has multiple installation groups, and the second scatterers between adjacent installation groups abut against each other.

[0029] The resulting technical effect is: in actual implementation, several groups of vibration reduction units are usually combined into a mounting structure, multiple second scatterers in one mounting structure are fixedly connected, and then the second scatterers between adjacent mounting structures are abutted.

[0030] Preferably, the second type of vibration reduction unit includes a frame structure, an elastic layer and a mass body, the frame structure is a long strip structure and is fixed to the track plate corresponding to the length direction of the rail, a plurality of square grooves are arranged side by side on the frame structure, the mass body is fixed in the square grooves, and the elastic layer is arranged between the mass body and the side walls of the square grooves.

[0031] The resulting technical effect is: on the basis of the setting of the first type of vibration damping unit, in order to improve the vibration damping effect, a second type of vibration damping unit is usually arranged on the track plate, thereby improving the vibration damping effect of the overall structure.

[0032] Preferably, a vibration gap of 10 mm is reserved between the elastic layer, the mass body and the track plate respectively.

[0033] The resulting technical effect is that the gap between the mass body, the elastic layer and the track plate is the prerequisite for the vibration reduction unit to exert its vibration reduction effect. The shear deformation of the elastic layer is used to achieve lower support stiffness and achieve track plate vibration control in a lower frequency range.

[0034] Preferably, the mass bodies in a plurality of square slots in the same row have different sizes, the masses of the mass bodies in adjacent square slots corresponding to the same row satisfy a linear variation rule, and the masses of the mass bodies in the square slots corresponding to adjacent rows are the same or different.

[0035] The resulting technical effect is to avoid resonance between the additional vibration reduction structure and the track structure. It can be understood that each substructure can control the vibration of a frequency band. If all substructures are arranged in the same way, the frequency band cannot be widened. Therefore, the mass or stiffness of adjacent substructures is randomly detuned, that is, the control frequency bands of adjacent substructures are staggered, thereby widening the vibration control range.

[0036] The present invention also discloses a design method of a random detuning track vibration reduction system, which comprises the following steps:

[0037] Step 1: Identify the vibration band gap characteristics of ballastless track

[0038] Conduct periodic characteristics and attenuation domain analysis of the ballastless track structure itself, and calculate the elastic wave band gap frequency range of the ballastless track structure based on the periodic characteristics of the track structure, fastener parameters, and ballastless track bed structure parameters;

[0039] Step 2: Design the basic vibration reduction unit

[0040] The vibration reduction unit is a local resonance structure unit. The vibration reduction unit is composed of a scatterer, a viscoelastic body and a constraint layer. The initial design parameters of the vibration reduction unit, including mass, elastic layer modulus and installation position, are designed. First, based on the control target frequency and the mass-spring system, the formula is used.

[0041]

[0042] The preliminary design values ​​of the mass of each scatterer and the modulus of the elastic layer are given. The parameters of each mass body are obtained through dynamic calculation, f is the control target frequency, k is the elastic coefficient, and then a refined finite element model of the rail-vibration reduction unit is established to analyze the influence of parameters such as mass, stiffness and installation position on the control frequency band, so as to determine the initial design parameters of the vibration reduction unit; the main frequency of the vibration reduction unit is close to the band gap frequency of the track structure, so that the vibration reduction unit structure attached to the rail or track plate has a coupling effect with the ballastless track structure, thereby maximizing the band gap range;

[0043] Step 3: Design the structural parameters of the detuned vibration reduction unit

[0044] The parameters of the vibration reduction unit structure are randomly detuned, including: scatterer weight, viscoelastic body stiffness and installation position, etc. These parameters obey a uniform distribution with a mean value of A1 and a coefficient of variation of δ1; the mean value is the initial design value before detuning is considered, and in the second step, the coefficient of variation can be taken as 0.1 to 0.5 according to experience; the detuning parameters and the degree of detuning are determined by the objective functions such as no structural resonance after the vibration reduction unit is installed and the increase of the vibration reduction frequency band;

[0045] Step 4: Add other control bands that need attention

[0046] According to the target control frequency band, the second or third type of vibration reduction unit is set. The second or third type of vibration reduction unit also adopts a random detuning design, and sets the key parameters of uniform distribution with a mean value of A2 or A3 and a coefficient of variation of δ2 or δ3;

[0047] Step 5: Evaluate the vibration reduction effect of the vibration reduction system

[0048] The vibration attenuation domain and vibration response characteristics of the random detuning vibration reduction system of ballastless track are analyzed, and the vibration reduction effect of the random detuning vibration reduction system is predicted.

[0049] The beneficial technical effect of the present invention is: based on the random detuning design concept and combined with the phononic crystal band gap theory, the phononic crystal elastic wave band gap is coupled with the band gap of the ballastless track structure itself to achieve track structure vibration control, and the random detuning parameters of the vibration reduction structure are further designed to suppress the resonance peak and widen the vibration reduction frequency band.

[0050] Preferably, in the step one, based on the phononic crystal elastic wave theory, the elastic wave band gap range of the ballastless track structure itself is calculated to obtain the frequency and vibration mode at the boundary of the elastic wave band gap; in the step two, the main frequency of the vibration reduction unit is close to the band gap frequency of the track structure, and the vibration mode of the vibration reduction unit is coupled with the significant vibration mode of the track structure, so that the additional local resonance structure and the ballastless track structure produce a coupling effect, thereby maximizing the band gap range; in the step five, firstly, the vibration attenuation domain range of the ballastless track random detuning vibration reduction system is analyzed to evaluate the vibration reduction range, and then the vibration response of the track structure under the action of simple harmonic load is calculated to evaluate that no obvious resonance response appears in the structure, and finally, a dynamic coupling analysis model of the vehicle-track-random detuning vibration reduction system is established, and the vibration response of the track structure and the vibration response of the structure under the track plate are used to predict the vibration reduction effect of the random detuning vibration reduction system. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a structural diagram of a random detuning track vibration reduction system of the present invention;

[0052] Figure 2 This is a partial enlarged view of a random detuning track vibration reduction system of the present invention;

[0053] Figure 3 This is a structural diagram of a vibration reduction unit of a random detuning track vibration reduction system of the present invention;

[0054] Figure 4 This is a layout diagram of the internal scatterers of a vibration reduction unit of a random detuning track vibration reduction system of the present invention;

[0055] Figure 5 This is an application diagram of the second type of vibration reduction unit of a random detuning track vibration reduction system of the present invention;

[0056] Figure 6 This is the structural diagram of the traditional ballastless track;

[0057] Figure 7 This is the vibration attenuation range of the traditional ballastless track;

[0058] Figure 8The figure is a comparison diagram of the vibration reduction effect between the present invention and a common dynamic vibration absorber.

[0059] 1 rail member, 2 fastener system, 3 track plate, 4 vibration reduction unit, 41 first type vibration reduction unit, 411 viscoelastic body, 4111 first slot cavity, 4112 second slot cavity, 4113 third slot cavity, 4114 fourth slot cavity, 4115 fifth slot cavity, 4116 sixth slot cavity, 412 constraint layer, 413 scatterer, 4131 first scatterer, 4132 second scatterer, 4133 third scatterer, 4134 fourth scatterer, 4135 fifth scatterer, 4136 sixth scatterer, 42 second type vibration reduction unit, 421 frame structure, 422 elastic layer, 423 mass body. DETAILED DESCRIPTION

[0060] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] See the attached Figures 1 to 8 According to an embodiment of the present invention, a random detuning track vibration reduction system comprises:

[0062] Rail member 1, which is actually a steel rail, is arranged in groups and at intervals on a track plate 3, which is a ballastless track plate, and a fastener system 2 is arranged between the rail member 1 and the track plate 3;

[0063] The vibration reduction unit 4 is actually an additional local vibration reduction unit. There are multiple groups of vibration reduction units 4, and the multiple groups of vibration reduction units 4 are arranged on the inner and outer sides of the track member 1 or the track plate, that is, they can be arranged on the track member, can also be arranged on the track plate, and can also be arranged on the track member and the track plate at the same time;

[0064] The multiple groups of vibration-damping units 4 on the same side of the rail member 1 correspond to the longitudinal (i.e., axial) quasi-periodic distribution of the rail member 1, which can be understood as an approximately periodic distribution. This is to avoid resonance between the additional local vibration-damping units and the periodic track structure. The vibration-damping units on both sides of the rail member 1 are symmetrically arranged or staggered, which requires consideration of the structural form of the rail member. When the fasteners are of a symmetrical structure, the vibration-damping units on both sides of the rail member can be staggered or symmetrically arranged; the main frequency of the vibration-damping unit 4 is close to the band gap frequency of the track structure, and the vibration mode of the vibration-damping unit is coupled with the vibration mode of the track structure, so that the resonance structure of the vibration-damping unit produces a coupling effect with the ballastless track structure, thereby enlarging the band gap range and reducing the transmission of the track structure vibration to the outside world.

[0065] Specifically, the vibration reduction unit 4 includes a first type of vibration reduction unit 41 and a second type of vibration reduction unit 42 . The first type of vibration reduction unit 41 is arranged on the rail member 1 , and the second type of vibration reduction unit 42 is arranged on the track plate 3 .

[0066] The first type of vibration reduction unit 41 includes a viscoelastic body 411, a constraint layer 412 and a scatterer 413. The viscoelastic body 411 is fixed on the side of the rail 1 and can be connected by an adhesive material or fixed on the rail using a clamp. The constraint layer 412 is fixed on the outer side of the viscoelastic body 411 away from the rail 1. The viscoelastic body 411 is provided with a plurality of grooves inside, and the plurality of grooves penetrate both ends of the viscoelastic body 411. There are multiple groups of scatterers 413, which are respectively installed in the grooves.

[0067] The viscoelastic body is rubber, polyurethane or viscoelastic damping material, the scatterer is a metal structure, and the constraint layer is a hard material plate. The function of the constraint layer is to constrain the viscoelastic body and improve the damping energy dissipation effect of the viscoelastic body. In addition, since the viscoelastic body usually has a low stiffness, the high stiffness of the constraint layer can provide conditions for the integrity of the structure and the installation of the fixture. The fixture can be installed through the bottom of the rail and will not affect the normal operation of the train.

[0068] More specifically, the viscoelastic body 411 in each vibration reduction unit is divided into five substructures in the axial direction, and the cross section of the viscoelastic body 411 is divided into a first half zone and a second half zone, the first half zone is close to the side of the rail member 1, and the second half zone is close to the side of the constraint layer 412, the first half zone is provided with a first groove cavity 4111, a second groove cavity 4112 and a third groove cavity 4113 in sequence from top to bottom in the first half zone, and the fourth groove cavity 4114, the fifth groove cavity 4115 and the sixth groove cavity 4116 are provided in sequence from top to bottom in the second half zone, and the scatterers include a first scatterer 4131, a second scatterer 4132, a third scatterer 4133, a fourth scatterer 4134, a fifth scatterer 4135 and a sixth scatterer 4136, and are respectively installed in the first groove cavity 4111, the second groove cavity 4112, the third groove cavity 4113, the fourth groove cavity 411 4. In the fifth slot cavity 4115 and the sixth slot cavity 4116, multiple second scatterers 4132 connect multiple sub-structures in series, and the first scatterer 4131, the third scatterer 4133, the fourth scatterer 4134, and the fifth scatterer 4135 are correspondingly in the sub-structures, and the first scatterers 4131, the third scatterer 4133, the fourth scatterer 4134, and the fifth scatterer 4135 in adjacent sub-structures are periodically spaced in the axial direction. Although each vibration reduction unit is divided into five sub-structures, these five sub-structures are designed as one body, just to distinguish that the scatterers other than the second scatterer and the sixth scatterer have discrete characteristics. It can be understood that the second scatterer and the sixth scatterer are continuous structures. On the one hand, they connect the sub-structures in series, and on the other hand, they guide the vibration of the transfer rail to the vibration reduction unit for energy consumption.

[0069] In specific implementation, three groups of vibration-damping units 4 on the same side of the rail member 1 constitute an installation group (such as three-span fasteners, 1.8m), and the vibration-damping units in the same installation group are connected in series through the second scatterer 4132. One side of the rail member 1 has multiple installation groups, and adjacent installation groups are connected through the second scatterer 4132.

[0070] In other embodiments, the second type of vibration reduction unit 42 includes a frame structure 421, an elastic layer 422 and a mass body 423. The frame structure 421 is a long strip structure and is fixed on the track plate 3 corresponding to the length direction of the rail member 1. A plurality of square grooves are arranged side by side on the frame structure 421. The mass body 423 is fixed in the square grooves, and the elastic layer 422 is arranged between the mass body 423 and the side walls of the square grooves.

[0071] It should be noted that a vibration gap of 10 mm is reserved between the elastic layer 422 and the mass body 423 and the track plate 3 .

[0072] The mass bodies 423 in multiple square slots on the same row have different sizes. The masses of the mass bodies 423 in adjacent square slots corresponding to the same row satisfy a linear variation rule. The masses of the mass bodies 423 in square slots corresponding to adjacent rows are the same or different.

[0073] Specific case description, Case 1:

[0074] Ordinary ballastless track structure Figure 6-7 As shown in Figure 1, it consists of rails, fastener systems, and track plates. The existing structure's vibration reduction capacity is mainly determined by the fasteners, but when the fastener stiffness decreases, it will cause the rail vibration response to be too large, causing rail corrugation. In order to improve the vibration reduction effect of the track structure, the proposed random detuned rail vibration reduction system is shown in Figure 1. Figure 1 As shown, vibration-damping units are attached to the left and right sides of the rail. The vibration-damping units are arranged approximately periodically along the longitudinal direction of the rail (not completely periodic, to avoid resonance problems between the additional vibration-damping structure and the periodic track structure), and the initial spacing between two adjacent unit groups on the same side is consistent, because they are arranged between two fasteners, and the fastener spacing of the track structure is the same. It is also possible to introduce detuning design parameters (i.e., random detuning of the installation position) to randomly adjust the installation positions of adjacent unit groups (including the substructures in each unit) to broaden the vibration reduction range and avoid resonance caused by structural periodicity.

[0075] The vibration reduction structure within the fastener spacing is a basic unit, and the left and right sides of the rails are staggered, such as Figure 2As shown, multiple outer basic units and multiple inner basic units are arranged in a staggered manner. The purpose of the staggered arrangement is to avoid the structural resonance problem caused by a completely symmetrical structure, which is also similar to a detuned design method. If the structure is completely periodic and symmetrical, the structural vibration will be significantly enhanced at the resonant frequency position.

[0076] Each basic unit has five substructures, such as Figure 3 and Figure 4 As shown. The basic vibration reduction unit consists of a constraint layer, a viscoelastic body and a scatterer. The vibration reduction unit is attached to the rail through the side and can be fixed by gluing or by clamping on the constraint layer. The scatterers in the basic unit are composed of two types of structures, one is a continuous structure (the second scatterer and the sixth scatterer), and the other is a discrete structure (the first scatterer, the third scatterer, the fourth scatterer, and the fifth scatterer). Both the continuous structure and the discrete structure are metal structures. The continuous structure can keep adjacent vibration reduction units connected, and the discrete structure makes multiple substructures in a vibration reduction unit also approximately periodic structures.

[0077] In order to expand the vibration reduction effect of the vibration reduction system, the elastic wave band gap range of the track structure itself is first calculated as follows: Figure 7 As shown. It can be seen that without vibration reduction measures, the ballastless track structure only has an extremely narrow band gap attenuation domain at low frequencies below 150 Hz and near 1000 Hz, and most of the structural vibrations can propagate freely. Therefore, by designing the parameters of the second and sixth scatterers of the continuous structure, including their cross-sectional inertia moment, cross-sectional shape and mass density, the additional vibration reduction system can produce a coupling effect with the band gap near 1000 Hz, thereby widening the vibration band gap in this frequency range. After the coupling band gap, in order to further control other frequencies, such as 300-400 Hz medium-frequency vibrations, the mass, position and shape of the first, third, fourth and fifth scatterers of the discrete structure can be designed so that the main frequency of the substructure is close to the target frequency. At this time, the vibration of the track structure can be transmitted to the additional vibration reduction system and dissipated in the scatterers.

[0078] Layout relationship and shape influence of the first to sixth scatterers:

[0079] The masses constructed by each discrete structure are randomly detuned and designed in a rhombus or rectangular shape to enhance its shear viscoelastic effect, thereby dissipating energy. In addition, the cross-sectional arrangement is divided into two sections (the first half and the second half). The left section is far away from the rails and can control the lateral bending and torsional vibration of the rails, so it is designed as a rhombus scatterer with sharp corners; the right section is close to the rails and mainly controls the vertical vibration, which requires a higher mass and is designed as a rectangular body.

[0080] At the same time, based on the idea of ​​random detuning, the parameters of the adjacent substructures and the first, third, fourth and fifth scatterers of the adjacent basic units are optimized. The initial design quality parameters are m1, m2, m3 and m4 respectively; the initial position design parameters are d1, d2, d3 and d4.

[0081] The above parameters are designed to be uniformly distributed with a coefficient of variation of δ1, that is, the mass of the first scatterer is

[0082] Location is Therefore, the first scatterer in the rail vibration reduction system is randomly distributed along the longitudinal direction of the rail, including random mass and random position. Considering random detuning, the coefficient of variation can be taken as 0.1 to 0.5 according to experience.

[0083] In order to verify the rationality of the design method, with the goal of matching the pinned-pinned resonance frequency (bandgap boundary frequency) of the track structure near 1000Hz, the initial design mass of the four scatterers is set to m1=1.5kg, the elastic layer stiffness modulus is 1.2Mpa, and the scatterer mass variation coefficient δ1=0.3. Under the premise of the same total added mass, the vibration reduction effect of the traditional single-degree-of-freedom vibration absorber and the random detuned vibration reduction system designed by this method are compared. Figure 8 It can be seen that the additional vibration reduction structure is coupled with the band gap of the track structure itself, and under the random detuning design, the attenuation domain is further widened.

[0084] Case 2: Random detuning vibration reduction system for ballastless track structure

[0085] On the basis of Case 1, in order to further control the transmission of low-frequency vibration to the lower foundation, a local resonance structure with random detuning characteristics is attached to the track plate.

[0086] The structure has the following characteristics: a basic unit consists of a frame structure, an elastic layer and a mass body. The frame structure is connected to the track plate, and a 10mm gap is reserved between the elastic layer and the mass body and the track plate to reserve space for the vibration of the scatterer. The vibration reduction system on the track plate consists of two rows of local resonance structures. Each mass body and elastic layer on each row is different, and their sizes satisfy the linear change law. From one end to the other, the minimum mass body is 10kg, and the mass of the mass body gradually increases in steps of 2kg. The corresponding elastic layer also gradually changes. The designed shear stiffness is a minimum of 1.2e5N / m and a maximum of 4e6N / m. The other row of mass bodies has the characteristics of large mass in the middle and small mass at both ends.

[0087] By matching the local resonance frequencies of the mass bodies, the frequencies of adjacent local resonance units are controlled at intervals of 10 Hz, thus achieving low-frequency vibration control in the range of 10 to 100 Hz.

[0088] At the same time, the track structure vibration is effectively controlled through the comprehensive control of the rail random detuning vibration reduction system and the track plate random detuning vibration reduction system.

[0089] It is understandable that each substructure can control the vibration of a frequency band. If all substructures are the same, they can only control this frequency band. Therefore, the mass or stiffness of adjacent substructures is randomly detuned, that is, the control frequency bands of adjacent substructures are staggered, thereby widening the vibration control range. Therefore, when designing, the mass of the mass body is linearly increased, and the elastic layer is also changed accordingly to achieve the widening of the control frequency band. The purpose of setting the other row of structures to be large in the middle and small in the two sections is also to widen the vibration control range, and the control frequency bands of the two rows of structures are inconsistent and have intersections, thereby covering 10 to 100 Hz.

[0090] The present invention also discloses a design method of a random detuning track vibration reduction system, which comprises the following steps:

[0091] Step 1: Identify the vibration band gap characteristics of ballastless track

[0092] Conduct periodic characteristics and attenuation domain analysis of the ballastless track structure itself, and calculate the elastic wave band gap frequency range of the ballastless track structure based on the periodic characteristics of the track structure, fastener parameters, and ballastless track bed structure parameters;

[0093] Step 2: Design the basic vibration reduction unit

[0094] The vibration reduction unit is a local resonance structure unit. The vibration reduction unit consists of a scatterer, a viscoelastic body, and a constraint layer. The initial design parameters of the vibration reduction unit are designed, including mass, elastic layer modulus, and installation position. First, based on the control target frequency and the mass-spring system, the formula is used.

[0095]

[0096] The mass of each scatterer and the preliminary design value of the elastic layer modulus are given, f is the control target frequency, k is the elastic coefficient, and then a refined finite element model of the rail-vibration reduction unit is established to analyze the influence of parameters such as mass, stiffness and installation position on the control frequency band, so as to determine the initial design parameters of the vibration reduction unit. The main frequency of the vibration reduction unit is close to the band gap frequency of the track structure, so that the vibration reduction unit structure attached to the rail or track plate has a coupling effect with the ballastless track structure, maximizing the band gap range;

[0097] Step 3: Design the structural parameters of the detuned vibration reduction unit

[0098] The parameters of the vibration reduction unit structure are randomly detuned, including the weight of the scatterer, the stiffness of the viscoelastic body, and the installation position. Based on the initial design parameters, these parameters obey a uniform distribution with a mean of A1 (i.e., the initial design parameters) and a coefficient of variation of δ1. The coefficient of variation can be 0.1 to 0.5. The detuning parameters and the degree of detuning are determined by the objective function of not causing structural resonance and increasing the vibration reduction frequency band after the vibration reduction unit is installed.

[0099] Step 4: Add other control bands that need attention

[0100] According to the target control frequency band, the second or third type of vibration reduction unit is set. The second or third type of vibration reduction unit also adopts a random detuning design, and sets the key parameters of uniform distribution with a mean value of A2 or A3 and a coefficient of variation of δ2 or δ3;

[0101] Step 5: Evaluate the vibration reduction effect of the vibration reduction system

[0102] The vibration attenuation domain and vibration response characteristics of the random detuning vibration reduction system of ballastless track are analyzed, and the vibration reduction effect of the random detuning vibration reduction system is predicted.

[0103] Specifically, in step one, based on the phononic crystal elastic wave theory, the elastic wave band gap range of the ballastless track structure itself is calculated, and the frequency and vibration mode at the boundary of the elastic wave band gap are obtained; the ballastless track structure has the characteristic of being arranged periodically along the longitudinal direction of the line, and its basic unit is a structure within the length of the track plate or the length of the fastener spacing. The track structure itself is a periodic structure and has a band gap characteristic. Based on the phononic crystal elastic wave theory, the elastic wave band gap range of the ballastless track structure itself is calculated, and the frequency and vibration mode at the boundary of the elastic wave band gap are obtained. The purpose of this step is to determine the vibration characteristics of the track structure itself, so that when designing an additional vibration reduction system, the vibration mode of the vibration reduction system is coupled with the vibration mode of the track structure, especially at the boundary of the elastic wave of the track structure. The coupling effect is generated, and the band gap range can be effectively expanded to maximize the vibration effect;

[0104] In step 2, the main frequency of the vibration reduction unit is close to the band gap frequency of the track structure, and the vibration mode of the vibration reduction unit is coupled with the significant vibration mode of the track structure, so that the additional local resonance structure and the ballastless track structure produce a coupling effect, thereby maximizing the band gap range;

[0105] In order to make the local resonance structure and the track structure significantly coupled at the main frequency, the direction of local vibration movement should be the same as the direction of movement of the rail or track plate. In order to further transmit the vibration of the track structure to the additional local resonance structure, a continuous structure is inserted into the design of the vibration reduction unit, and the phononic crystal elastic wave passband mechanism is introduced, that is, the continuous structure can effectively transmit vibration, so that the structure can guide the vibration of the track structure to the vibration reduction system and transmit it longitudinally along the line, and at the same time consume the vibration energy through the vibration of the local resonance unit. Therefore, the vibration reduction unit consists of two types: a continuous structure (generating an elastic wave passband to guide the track vibration to the vibration reduction system) and a local resonance structure (generating an elastic wave band gap to consume vibration energy).

[0106] In step five, the vibration attenuation domain of the ballastless track random detuning vibration reduction system is first analyzed to evaluate the vibration reduction range. Then, the vibration response of the track structure under the action of simple harmonic load is calculated to evaluate that no obvious resonance response occurs in the structure. Finally, a dynamic coupling analysis model of the vehicle-track-random detuning vibration reduction system is established to predict the vibration reduction effect of the random detuning vibration reduction system through the vibration response of the track structure and the vibration response of the structure under the track plate.

[0107] The core principle of this method is to design a random detuned track vibration reduction system based on the passband and forbidden band mechanism of phononic crystal elastic waves and taking into account the periodic characteristics of the track structure itself.

[0108] First, in the random detuned vibration reduction system, its basic unit is composed of a discrete local resonance unit and a continuous guide structure. Therefore, based on these two types of structures, the vibration of the track structure can be guided to the additional vibration reduction system through the continuous structure based on the passband mechanism, so as to guide and propagate the vibration of the track structure, and then based on the bandgap mechanism, the vibration is transferred to the local oscillator through the discrete local resonance structure and dissipated.

[0109] In addition, in order to solve the problem that the existing vibration reduction measures do not have a sufficient vibration reduction frequency band, some local resonance units in the additional structure are coupled with the band gap of the periodic track structure itself, thereby expanding the band gap range of the track structure. Vibration within the band gap range will be difficult to transmit in the track structure itself and can only propagate to the additional structure.

[0110] Furthermore, the vibration reduction effect of the local resonance unit is expanded through the random detuning structure, overcoming the shortcomings of the single frequency control of the traditional dynamic vibration absorber. At the same time, the resonance of the periodic structure itself is avoided by randomizing the stiffness parameters, mass parameters and installation position parameters, thereby achieving a better vibration reduction effect while eliminating the structural resonance problem caused by the traditional additional vibration reduction system.

[0111] As for the device and the method of use disclosed in the embodiment, since they correspond to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0112] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A random detuning track vibration reduction system, characterized in that: include: Rail members (1), the rail members (1) are arranged in groups at intervals on a track plate (3), and a fastener system (2) is arranged between the rail members (1) and the track plate (3); A vibration damping unit (4), wherein the vibration damping unit (4) comprises a plurality of groups, and the plurality of groups of the vibration damping units (4) are arranged on both inner and outer sides of the rail member (1) or on the track plate, and the plurality of groups of the vibration damping units (4) on the same side of the rail member (1) are quasi-periodically distributed in the longitudinal direction of the rail member (1), and the vibration damping units on both sides of the rail member (1) are symmetrically arranged or staggered, and the main frequency of the vibration damping unit (4) is close to the band gap frequency of the track structure, and the vibration mode of the vibration damping unit is coupled with the vibration mode of the track structure, so that the resonance structure of the vibration damping unit and the ballastless track structure produce a coupling effect, thereby enlarging the band gap range.

2. A random detuning track vibration reduction system according to claim 1, characterized in that: The vibration damping unit (4) comprises a first type of vibration damping unit (41) and a second type of vibration damping unit (42), wherein the first type of vibration damping unit (41) is arranged on the rail member (1), and the second type of vibration damping unit (42) is arranged on the track plate (3).

3. A random detuning track vibration reduction system according to claim 2, characterized in that: The first type of vibration reduction unit (41) comprises a viscoelastic body (411), a constraint layer (412) and a scatterer (413); the viscoelastic body (411) is fixed to the side of the rail member (1); the constraint layer (412) is fixed to the outside of the viscoelastic body (411) away from the rail member (1); a plurality of groove cavities are provided inside the viscoelastic body (411); the plurality of groove cavities pass through both ends of the viscoelastic body (411); and the scatterers (413) are provided in a plurality of groups and are respectively installed in the groove cavities.

4. A random detuning track vibration reduction system according to claim 3, characterized in that: The viscoelastic body (411) is divided into a plurality of substructures in the axial direction, and the cross section of the viscoelastic body (411) is divided into a first half zone and a second half zone, wherein the first half zone is close to the side of the rail member (1), and the second half zone is close to the side of the constraint layer (412), and the first half zone is provided with at least a first slot cavity (4111), a second slot cavity (4112), and a third slot cavity (4113) in sequence from top to bottom, and the second half zone is provided with at least a fourth slot cavity (4114), a fifth slot cavity (4115), and a sixth slot cavity (4116) in sequence from top to bottom, and the scatterers at least include a first scatterer (4131), a second scatterer (4132), a third scatterer (4133), a fourth scatterer (4134), and a fifth scatterer (4136). 5) and the sixth scatterer (4136) are respectively installed in the first slot cavity (4111), the second slot cavity (4112), the third slot cavity (4113), the fourth slot cavity (4114), the fifth slot cavity (4115) and the sixth slot cavity (4116) in a one-to-one manner, a plurality of the second scatterers (4132) and a plurality of the sixth scatterers (4136) connect a plurality of sub-structure parts in series, the first scatterer (4131), the third scatterer (4133), the fourth scatterer (4134) and the fifth scatterer (4135) are correspondingly arranged in the sub-structure parts, and the first scatterer (4131), the third scatterer (4133), the fourth scatterer (4134) and the fifth scatterer (4135) in adjacent sub-structure parts are periodically spaced in the axial direction.

5. A random detuning track vibration reduction system according to claim 4, characterized in that: At least two groups of vibration-damping units (4) on the same side of the rail member (1) form an installation group, and the vibration-damping units in the same installation group are connected in series via a second scatterer (4132) or a sixth scatterer (4136). One side of the rail member (1) has a plurality of installation groups, and the second scatterers (4132) between adjacent installation groups abut against each other.

6. The random detuning track vibration reduction system according to claim 2, characterized in that: The second type of vibration reduction unit (42) comprises a frame structure (421), an elastic layer (422) and a mass body (423); the frame structure (421) is a long strip structure and is fixed on the track plate (3) in the length direction of the corresponding rail member (1); a plurality of square grooves are arranged side by side on the frame structure (421); the mass body (423) is fixed in the square grooves; and the elastic layer (422) is arranged between the mass body (423) and the side wall of the square groove.

7. The random detuning track vibration reduction system according to claim 6, characterized in that: A vibration gap of 10 mm is reserved between the elastic layer (422) and the mass body (423) and the track plate (3).

8. The random detuning track vibration reduction system according to claim 6, characterized in that: The mass bodies (423) in the plurality of square slots in the same row have different sizes, the masses of the mass bodies (423) in the adjacent square slots corresponding to the same row satisfy a linear variation rule, and the masses of the mass bodies (423) in the square slots corresponding to adjacent rows are the same or different.

9. A design method for a random detuning track vibration reduction system according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: Identify the vibration band gap characteristics of ballastless track Conduct periodic characteristics and attenuation domain analysis of the ballastless track structure itself, and calculate the elastic wave band gap frequency range of the ballastless track structure based on the periodic characteristics of the track structure, fastener parameters, ballastless track bed structure, and track slab support stiffness parameters; Step 2: Design the basic vibration reduction unit The vibration reduction unit is a local resonance structure unit. The vibration reduction unit is composed of a scatterer, a viscoelastic body and a constraint layer. The initial design parameters of the vibration reduction unit, including mass, elastic layer modulus and installation position, are designed. First, based on the control target frequency and the mass-spring system, the formula is used. The mass of each scatterer and the preliminary design value of the elastic layer modulus are given. The parameters of each mass body are obtained through dynamic calculation, k is the elastic coefficient, and then a refined finite element model of the rail-vibration reduction unit is established to analyze the influence of parameters such as mass, stiffness and installation position on the control frequency band, so as to determine the initial design parameters of the vibration reduction unit; The main frequency of the vibration reduction unit is close to the band gap frequency of the track structure, so that the vibration reduction unit structure attached to the rail member or track plate produces a coupling effect with the ballastless track structure, thereby maximizing the band gap range; Step 3: Design the structural parameters of the detuned vibration reduction unit The parameters of the vibration reduction unit structure are randomly detuned, including the weight of the scatterer, the stiffness of the viscoelastic body, and the installation position. These parameters are uniformly distributed with a mean value of A1 and a coefficient of variation of δ1. The mean value is the initial design value before detuning is considered, which is obtained in the second step. For the coefficient of variation, it can be taken as 0.1 to 0.5 according to experience. The detuning parameters and the degree of detuning are determined by the objective function that the vibration reduction unit does not cause structural resonance and the vibration reduction frequency band range is increased after the vibration reduction unit is installed. Step 4: Add other control bands that need attention According to the target control frequency band, the second or third type of vibration reduction unit is set. The second or third type of vibration reduction unit also adopts a random detuning design, and sets the key parameters of uniform distribution with a mean value of A2 or A3 and a coefficient of variation of δ2 or δ3; Step 5: Evaluate the vibration reduction effect of the vibration reduction system The vibration attenuation domain and vibration response characteristics of the random detuning vibration reduction system of ballastless track are analyzed, and the vibration reduction effect of the random detuning vibration reduction system is predicted.

10. The design method of a random detuning track vibration reduction system according to claim 9, characterized in that: In the step 1, based on the phononic crystal elastic wave theory, the elastic wave band gap range of the ballastless track structure itself is calculated to obtain the frequency and vibration mode at the boundary of the elastic wave band gap; in the step 2, the main frequency of the vibration reduction unit is close to the band gap frequency of the track structure, and the vibration mode of the vibration reduction unit is coupled with the significant vibration mode of the track structure, so that the additional local resonance structure and the ballastless track structure produce a coupling effect, thereby maximizing the band gap range; in the step 5, firstly, the vibration attenuation domain range of the ballastless track random detuning vibration reduction system is analyzed to evaluate the vibration reduction range, and then the vibration response of the track structure under the action of simple harmonic load is calculated to evaluate that no obvious resonance response appears in the structure, and finally, a vehicle-track-random detuning vibration reduction system dynamic coupling analysis model is established, and the vibration response of the track structure and the vibration response of the structure under the track plate are used to predict the vibration reduction effect of the random detuning vibration reduction system.

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